Method for manufacturing an adhesive substrate with a die-cavity sidewall

ABSTRACT

A method for manufacturing an adhesive substrate with a die-cavity sidewall is disclosed. A region for forming die-cavity sidewall is defined on one surface of the substrate. The substrate is laminated with a sacrificial film, a partially cured resin is formed between the substrate and the sacrificial film. And then, an aperture is routed through the substrate, the partially cured resin, and the sacrificial film. The aperture is located corresponding to the region so that the substrate has a die-cavity sidewall formed inside the aperture. Thereafter, the sacrificial film is removed to expose the partially cured resin on the substrate so that the substrate with a die-cavity sidewall can have good adhesion.

FIELD OF THE INVENTION

The present invention relates to a method for manufacturing a substrateassembly with a die cavity to accommodate a semiconductor chip and, moreparticularly, to a method for manufacturing an adhesive substrate with adie-cavity sidewall.

BACKGROUND OF THE INVENTION

In the field of semiconductor packages and modules, a substrate with adie cavity to accommodate a semiconductor chip is rather common. The diecavity comprises a die-cavity sidewall and a die-attached plane. Forcontrolling the height of the die-cavity sidewall and the coplanality ofthe die-attached plane, the die-cavity sidewall and the die-attachedplane are manufactured from two different substrates firstly, then byusing an adhesive layer to laminate the substrate with a die-cavitysidewall and the substrate with a die-attached plane for forming alaminated substrate assembly with a die cavity. As disclosed in U.S.Pat. No. 6,506,626 and U.S. patent application Publication No.2001/0046725, the substrate with a die-attached plane is a ball gridarray circuit board and the substrate with a die-cavity sidewall is ametal stiffener or spacer circuit board, both substrates are assembledto be a substrate assembly with a die cavity for manufacturing asemiconductor package or module with a faceup die cavity. As disclosedin U.S. Pat. No. 6,639,304 and U.S. Pat. No. 6,501,168, the substratewith a die-attached plane is a metal plate or metal core. Moreover, thesubstrate with a die-cavity sidewall is a circuit board with an openingor window. Both substrates are assembled for manufacturing semiconductorpackage or module with facedown die cavity.

Normally the adhesive layer used for laminating the two substratesmentioned above is acrylate film, liquid adhesive or prepreg. When theadhesive layer is a solid type or gummy type film such as acrylate filmor prepreg, it is necessary to punch or route an opening, then twosubstrates are laminated under the opening of the adhesive layer alignedto the die-attached plane of the substrate. However, due to the natureof the adhesive layer, the adhesive layer will stick to the tooling orattract unwanted particles during processes, which caused extra cleaningproblem for tooling and degradation of adhesion. Moreover, the arcylatefilm is very sensitive to moisture and only can reach JEDEC lever four.During the routing or punching processes, prepreg can be easily damagedand formed lots of resin flakes or particles.

When using liquid adhesive as an adhesive layer for bonding the twosubstrates mentioned above, as well known, the liquid adhesive needs toapply to the substrate with a die-cavity sidewall or to the substratewith a die-attached plane via screen printing. In order to avoid thecontamination of liquid adhesive onto the die-cavity sidewall duringlaminating the substrates, the liquid adhesive must have higher adhesionwith proper surface tension and viscosity. If the liquid adhesivecontains solvent, after screen printing, the liquid adhesive layer willneed pre-bake or drying processes and then the two substrates mentionedabove are laminated and cured under higher temperatures. During thecuring processes, the curing conditions need extremely under control,any mistakes may force the liquid adhesive layer to flow to thedie-cavity sidewall or die-attached plane and cause the coplanalityissue for die attachment.

A method for manufacturing die cavity on a substrate is disclosed inU.S. Pat. No. 6,195,264. An adhesive layer with photosensitive materialcan be applied between the metal stiffener and printed circuit board. Asubstrate assembly with a die cavity will be formed after laminationsince the adhesive layer with photosensitive material can be exposed anddeveloped, therefore, no residual of the adhesive layer can be foundinside the die cavity. However, the requirements for the adhesive layerwith photosensitive material should have an excellent photosensitivityand easy photo processing characteristics, moreover, goodthermal-setting properties, adhesion, and heat conductivity. However,such kind of adhesive layer with photosensitive material is not easy toget which is in higher cost.

SUMMARY OF THE INVENTION

A main purpose of the present invention is to supply a method formanufacturing an adhesive substrate with a die-cavity sidewall. Asubstrate and a sacrificial film are laminated together with a partiallycured resin in-betweens. Then an aperture is routed through thesubstrate, the partially cured resin, and the sacrificial film, then, adie-cavity sidewall from the substrate is formed inside the aperture.Then by removing the sacrificial film, the partially cured resin will bekept on the substrate, moreover, the partially cured resin will notcontaminate the die-cavity sidewall, at the same time, the substratewill have good adhesion for laminating with the other substrate.

According to the present invention, a method for manufacturing anadhesive substrate with a die-cavity sidewall includes, firstly,providing a substrate with an attaching surface. At least a region forforming a die-cavity sidewall is defined on the attaching surface of thesubstrate. Next, the substrate is laminated with a sacrificial film witha partially cured resin in-betweens. An aperture is createdcorresponding to the region and passes through the substrate, thepartially cured resin, and the sacrificial film by routing or punching,therefore, a die-cavity sidewall will be formed in the substrate. Theaperture can be formed by routing, punching or the other method.Thereafter, by removing the sacrificial film, the partially cured resinis exposed on the substrate. Therefore, the adhesive substrate with adie-cavity sidewall can be laminated with another substrate with adie-attached plane to be a laminated substrate assembly with a diecavity that can be manufacturing with low cost and implemented in eitherfacedown or faceup semiconductor packages or modules.

DESCRIPTION OF THE DRAWINGS

FIG. 1A to FIG. 1D are cross-sectional views of an adhesive substratewith a die-cavity sidewall during manufacturing process in accordancewith the first embodiment of the present invention;

FIG. 2 is a three-dimensional view of a substrate forming withpre-cutting holes after lamination in accordance with the firstembodiment of the present invention;

FIG. 3 is a three-dimensional view of a substrate forming with aperturesafter lamination in accordance with the first embodiment of the presentinvention;

FIG. 4 is a cross-sectional view of a semiconductor package comprisingthe adhesive substrate with a die-cavity sidewall manufactured inaccordance with the first embodiment of the present invention;

FIG. 5A to FIG. 5D are cross-sectional views of an adhesive substratewith a die-cavity sidewall during the manufacturing process inaccordance with the second embodiment of the present invention;

FIG. 6 is a cross-sectional view of a semiconductor package comprisingthe adhesive substrate with a die-cavity sidewall manufactured inaccordance with the second embodiment of the present invention.

DETAIL DESCRIPTION OF THE INVENTION

Please refer to the drawings attached, the present invention will bedescribed by means of embodiments below. According to the presentinvention, the first embodiment discloses a method for manufacturing anadhesive substrate with a die N cavity sidewall. As shown in FIG. 1A,firstly the first substrate 110 is provided. The first substrate 110 hasthe first surface 111 and the second surface 112. In this embodiment,the first substrate 110 is a ball grid array (BGA) substrate forsemiconductor package or module with facedown die cavity. Normally, thefirst substrate 110 is a printed circuit board made of BT resin. Thefirst surface 111 is used to attach to the second substrate 210, isshown in FIG. 4. The first surface 111 defines at least one region 113for forming a die-cavity sidewall. The second surface 112 has aplurality of bonding fingers 114 for bonding wires and a plurality ofball pads 115 for solder balls.

Then, as shown in FIG. 1B, the first substrate 110 is laminated with asacrificial film 120. The sacrificial film 120 may be a low cost,etchable metal film, such as copper foil. Moreover, a partially curedresin 130 is formed between the first substrate 110 and the sacrificialfilm 120 to form a laminated substrate. The partially cured resin 130 iscured from 5 to 50%, and more particularly, the partially cured resin130 is cured 5 to 15%. After laminating the first substrate 110 with thesacrificial film 120, the partially cured resin 130 is pressed via thesacrificial film 120 to have an uniform thickness. Therefore, theformation of unwanted particles during processes and the contaminationof the partially cured resin 130 will be greatly reduced. Moreover, thepartially cured resin 130 can be easily processing and will not stick tothe tooling. The partially cured resin 130 has multi-stage thermosettingproperty, which can be partially cured (in B-stage) under proper curingtemperature and conditions. The partially cured resin 130 can be made ofepoxy resin, BT (Bismaleimide Triazine) resin or PI (Polyimide) resin.The partially cured resin 130 can be prepreg containing glass fibers,preferably, the partially cured resin 130 contains metal particles, suchas silver particles, to enhance heat conductivity of the partially curedresin 130.

Thereafter, as shown in FIG. 1C and FIG. 3, using routing or otherthrough hole forming methods, an aperture 140 is formed through thelaminated substrate which is made of the first substrate 110, thesacrificial film 120, and the partially cured resin 130. Referring toFIG. 2, before routing the aperture 140, at least one pre-cutting hole141 can be formed at periphery of the region 113. The pre-cutting hole141 was routed through the first substrate 110, the partially curedresin 130, and the sacrificial film 120. Preferably, the pre-cuttingholes 141 are located at the corners of the region 113. Next, theaperture 140 is formed by a routing machine, which is locatedcorresponding to the region 113 of the substrate 110. The aperture 140is routed through the first substrate 110, the partially cured resin130, and the sacrificial film 120 so that the first substrate 110 has adie-cavity sidewall 116 which is inside the aperture 140.

Thereafter, as shown in FIG. 1D, the sacrificial film 120 is removed tomake the partially cured resin 130 appear on the first surface 111 ofthe first substrate 110. The sacrificial film 120 can be removed byetching or peeling methods. Moreover, the partially cured resin 130 isformed prior to making the aperture 140, therefore, the die-cavitysidewall 116 will not be contaminated by the partially cured resin 130.Besides, the partially cured resin 130 with good adhesion is applied onthe first surface 111 of the first substrate 110 by printing or theother, which is ready for laminating a substrate with a die-attachedplane.

The first substrate 110 with the die-cavity sidewalls 116 is laminatedwith a second substrate 210 with a die-attached plane 211 to be asubstrate assembly with a die cavity which can be used to assembly acavity-down semiconductor package or module. As shown in FIG. 4, thecavity-down semiconductor package comprises the first substrate 110. Thepartially cured resin 130 is formed on the first surface 111 of thefirst substrate 110 to adhere the second substrate 210 with adie-attached plane 211. After laminating the first substrate 110 withthe second substrate 210, the die-cavity sidewall 116 of the firstsubstrate 110 and the die-attached plane 211 of the second substrate 210constitute a die cavity for accommodating a semiconductor chip 220.During the lamination of the first substrate 110 and the secondsubstrate 210, the partially cured resin 130 will not overflow tocontaminate the die-cavity sidewall 116 or the die-attached plane 211.Therefore, there is no alignment problem for adhesive layers.

In this embodiment, the second substrate 210 with the die-attached plane211 is a metal heat spreader. The semiconductor chip 220 is attached tothe die-attached plane 211 of the second substrate 210. Moreover, thechip 220 is inside the die-cavity sidewall 116 of the first substrate110, i.e., the semiconductor chip 220 is accommodated inside the diecavity formed by the die-cavity sidewall 116 and the die-attached plane211. A plurality of bonding wires 230 are used to electrically connect aplurality of bonding pads 221 of the semiconductor chip 220 with thebonding fingers 114 of the first substrate 110. Thereafter, a packagebody 240 is formed inside the die cavity formed by the die-cavitysidewall 116 and the die-attached plane 211. A plurality of solder balls250 are bonded on the ball pads 115. Finally, a semiconductor packagewith facedown die cavity is assembled.

Furthermore, in the present invention, the method of manufacturing anadhesive substrate with a die-cavity sidewall can be implemented toassemble a laminated substrate with a faceup die cavity. According tothe second embodiment of the present invention, as shown in FIG. 5A, thefirst substrate 310 is provided firstly. The first substrate 310 has afirst surface 311 and a second surface 312. In this embodiment, thefirst substrate 310 is a metal plate used as a stiffener forsemiconductor packages or modules. There is at least one region 313 forforming a die-cavity sidewall on the first surface 311. Thereafter, asshown in FIG. 5B, the first substrate 310 is laminated with asacrificial film 320. Moreover, a partially cured resin 330 is formedbetween the first substrate 310 and the sacrificial film 320 so as toform a laminated substrate. The surface of the sacrificial film 320 thatcontacts the partially cured resin 330 is a smooth surface for easypeeling. The sacrificial film 320 may be a paper carrier or metal foil.

Then, as shown in FIG. 5C, the region 313 is punched off to form anaperture 340 through the laminated substrate including the firstsubstrate 310, the sacrificial film 320, and the partially cured resin330. Therefore, a die-cavity sidewall 314 from the first substrate 310is formed inside the aperture 340. Thereafter, as shown in FIG. 5D, thesacrificial film 320 is removed by the method of peeling or etching sothat the partially cured resin 330 on the first surface 311 of the firstsubstrate 310 will be exposed.

Therefore, the first substrate 310 with the die-cavity sidewall 314,i.e., an adhesive stiffener, formed by the method mentioned above isadhesive because that the partially cured resin 330 is formed on thefirst substrate 310. The first substrate 310 with the die-cavitysidewall 314 can be implemented on a semiconductor package or modulewith a faceup die cavity, is shown in FIG. 6. A semiconductor packagecomprises the first substrate 310. The partially cured resin 330 isformed on the first surface 311 of the first substrate 310 to adhere thesecond substrate 410, such as a printed circuit board, which has adie-attached plane 411. A die cavity consists of the die-attached plane411 and the die-cavity sidewall 314 so as to accommodate a semiconductorchip 420. Normally, after laminating the first substrate 310 with thesecond substrate 410, the partially cured resin 330 can be completelycured. The semiconductor chip 420 is attached to the die-attached plane411 of the second substrate 410 and is positioned inside the die-cavitysidewall 314 of the first substrate 310. A plurality of bonding wires430 are used to electrically connect the bonding pads 421 of thesemiconductor chip 420 with the second substrate 410. Preferably, a heatspreader 440 can be adhered to the second surface 312 of the firstsubstrate 310. Then a plurality of solder balls 450 are bonded on thesecond substrate 410. Finally, a semiconductor package or module withfaceup cavity is assembled.

The above description of embodiments of this invention is intended to beillustrative and not limiting. Other embodiments of this invention willbe obvious to those skilled in the art in view of the above disclosure.

1. A method for manufacturing an adhesive substrate with a die-cavitysidewall, comprising: providing a first substrate, the first substratehaving a surface defining at least a region for forming the die-cavitysidewall; laminating the first substrate with a sacrificial film, apartially cured resin being formed between the first substrate and thesacrificial film; forming an aperture located corresponding to theregion of the first substrate, the aperture passing through the firstsubstrate, the partially cured resin and the sacrificial film in amanner that the first substrate has the die-cavity sidewall inside theaperture; and removing the sacrificial film to expose the partiallycured resin on the first substrate.
 2. The method of claim 1, whereinthe partially cured resin is cured from 5 to 50%.
 3. The method of claim1, wherein the partially cured resin has an uniform thickness.
 4. Themethod of claim 1, wherein the partially cured resin is a prepreg. 5.The method of claim 1, wherein the partially cured resin is selectedfrom one of the group of epoxy resin, BT(Bismaleimide Triazine) resin,or PI (Polyimide) resin.
 6. The method of claim 1, wherein the partiallycured resin contains metal particles.
 7. The method of claim 1, whereinthe sacrificial film is removed by peeling.
 8. The method of claim 1,wherein the sacrificial film is removed by etching.
 9. The method ofclaim 1, wherein the sacrificial film is a metal foil.
 10. The method ofclaim 1, wherein the aperture is formed by punching.
 11. The method ofclaim 1, wherein the aperture is formed by routing.
 12. The method ofclaim 11, further comprising: forming a pre-cutting hole through thefirst substrate, the partially cured resin and the sacrificial film forrouting the aperture.
 13. The method of claim 12, wherein thepre-cutting hole is located at the corner of the region of the firstsubstrate.
 14. The method of claim 1, wherein the first substrate is astiffener.
 15. The method of claim 14, wherein the first substrate is ametal plate.
 16. The method of claim 1, further comprising: adhering thepartially cured resin on the first substrate to a second substrate witha die-attached plane to form a die cavity.
 17. A method formanufacturing a semiconductor device, comprising: providing a firstsubstrate, the first substrate having a surface defining at least aregion for forming a die-cavity sidewall; laminating the first substratewith a sacrificial film, a partially cured resin being formed betweenthe first substrate and the sacrificial film; forming an aperturelocated corresponding to the region, the aperture passing through thesubstrate, the partially cured resin and the sacrificial film in amanner that the first substrate has a die-cavity sidewall inside theaperture; removing the sacrificial film to expose the partially curedresin on the substrate; adhering the partially cured resin on the firstsubstrate to a second substrate with a die-attached plane to form a diecavity; attaching a semiconductor chip to the die-attached plane of thesecond substrate; and electrically connecting the semiconductor chip andthe first substrate.
 18. The method of claim 17, wherein the partiallycured resin is cured from 5 to 50%.
 19. The method of claim 17, whereinthe partially cured resin has an uniform thickness.
 20. The method ofclaim 17, wherein the partially cured resin is a prepreg.
 21. The methodof claim 17, wherein the partially cured resin is selected from one ofthe group of epoxy resin, BT (Bismaleimide Triazine) resin, or PI(Polyimide) resin.
 22. The method of claim 17, wherein the partiallycured resin contains metal particles.
 23. The method of claim 17,wherein the sacrificial film is a metal foil.
 24. The method of claim17, wherein the sacrificial film is removed by peeling or etching. 25.The method of claim 17, wherein the first substrate is a cavity-downball grid array substrate.
 26. The method of claim 25, wherein thesecond substrate is a heat spreader.
 27. The method of claim 17, furthercomprising: forming a package body inside the die cavity.
 28. Anadhesive substrate with a die-cavity sidewall, comprising: a firstsubstrate, the first substrate having a surface defining at least aregion for forming the die-cavity sidewall; a partially cured resinformed on the surface of the first substrate; and a die-cavity sidewallformed corresponding to the region of the first substrate by forming anaperture passing through the first substrate and the partially curedresin.
 29. The substrate of claim 28, wherein the partially cured resinis cured from 5 to 50%.
 30. The substrate of claim 28, wherein thepartially cured resin is cured from 5 to 15%.
 31. The substrate of claim28, wherein the partially cured resin is laminated between the firstsubstrate and a sacrificial film.
 32. The substrate of claim 31, whereinthe partially cured resin has an uniform thickness.
 33. The substrate ofclaim 28, wherein the partially cured resin is a prepreg.
 34. Thesubstrate of claim 28, wherein the partially cured resin is selectedfrom one of the group of epoxy resin, BT(Bismaleimide Triazine) resin,or PI (Polyimide) resin.
 35. The substrate of claim 28, wherein thepartially cured resin contains metal particles.
 36. The substrate ofclaim 28, wherein the first substrate is a stiffener.
 37. The substrateof claim 36, wherein the first substrate is a metal plate.
 38. Thesubstrate of claim 28, further comprising: a second substrate with adie-attached plane, the partially cured resin on the first substrateadhering the second substrate to form a die cavity.